DevTools: [SSP] show source location for the newly inserted style rules.

To achieve the specified goal, the patch does the following:
- StylePropertiesSection.styleRule no longer has sourceURL as it could
be always fetched from styleRule.rule
- StylePropertiesSection._createRuleOrigin is receiving CSSRule and
ruleLocation as arguments
- BlankStylePropertiesSection is taught to infer the actual rule
location of the rule that will be inserted

Layout Test change: the CSSOM rule now don't show source location (used to be "located" on first line)

R=pfeldman, vsevik, apavlov

Review URL: https://codereview.chromium.org/474433004

git-svn-id: svn://svn.chromium.org/blink/trunk@180348 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Nuke TimelineAllEventsReceived event

BUG=403684,398785
R=pfeldman@chromium.org

Review URL: https://codereview.chromium.org/476773002

git-svn-id: svn://svn.chromium.org/blink/trunk@180349 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Nuke Timeline extension api

Timeline extension API is removed from DevTools front-end.

BUG=403684
R=pfeldman@chromium.org

Review URL: https://codereview.chromium.org/477103002

git-svn-id: svn://svn.chromium.org/blink/trunk@180350 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: make profiling lock global rather than per Target

We should pause any actions that could affect performance if any of the targets is being profiled, not only current target.

Compared to r180336 profiling lock is now initialized in Locks.js

BUG=403684
R=pfeldman@chromium.org

Review URL: https://codereview.chromium.org/472263002

git-svn-id: svn://svn.chromium.org/blink/trunk@180351 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Use profiling lock in ScreencastView to detect if Timeline or Profiler is started

Instead of listening to particular model notifications it is enough to listen for profiling lock changes.

BUG=403684
R=pfeldman@chromium.org

Review URL: https://codereview.chromium.org/471013002

git-svn-id: svn://svn.chromium.org/blink/trunk@180352 bbb929c8-8fbe-4397-9dbb-9b2b20218538